Relationships between invasive plant species occurrence and socio-economic variables in urban green spaces of southwestern British Columbia, Canada.
This study was conducted to address the relationship between socio-economic variables and invasive plant species occurrence in parks and natural areas in two cities of Metro Vancouver, British Columbia, Canada. Invasive plants inventory data in parks and natural areas were acquired from the cities of Surrey (surveyed in 2014-2016) and Coquitlam (surveyed in 2013-2015). Four socio-economic variables were extracted from the 2011 Canada Census, the 2016 National Household Survey, and the 2016 Survey of Household Spending: median household income, population density, single-detached house density, and household expenditure on gardening. Ten topographic/park variables (e.g., elevation, path and trail density) were obtained for each invasive plant observation point. Using an inhomogeneous Poisson point process modelling approach, the relationships between these socio-economic and topographic/park variables and the occurrences of three priority invasive plants-English ivy, knotweed species, and yellow archangel-were evaluated. Population density had positive associations with knotweed species occurrence in both cities as well as English ivy occurrence in Surrey. In Coquitlam, single-detached house density and median household income were identified as significant socio-economic variables for English ivy and yellow archangel, respectively. Results indicate that relationships between socio-economic variables and species occurrence vary with site and target species. This case study demonstrates a possible approach for linking common invasive plant field survey data and socio-economic data to establish relationships. The results can help land managers to establish cost-effective management strategies by providing valuable information needed for monitoring and pro-active management of invasive plants.